Myopia

A highly common vision condition is myopia, or nearsightedness. People diagnosed with myopia generally have difficulty seeing into the distance, which makes daily tasks like driving or watching a presentation or TV very taxing. In a normal eye rays of light are bent and reflected from the lens onto a single point on the retina, and it is this reflection that produces the image our brain interprets as sight.

In order for this to work the light has to be bent a certain way to make sure that the light focuses on the correct part of the retina. With myopia, the math is thrown off and the light rays do not project the image onto the retina, but rather to a point in front of the retina. The easiest explanation for this is that the myopic eye is somehow longer than the normal eye, which changes the relationship between the lens, the retina, and the light that is reflecting the image.

It was previously assumed that myopia was a hereditary condition, but recent research also cites other possible causes such as too much eye strain or close work. There is still a great deal of study to be done. To learn more about your vision visit our How The Eye Works page.

Myopia Treatment

There is a range of treatment options for myopia depending on lifestyle choices as well as the severity of the impairment. Glasses and contact lenses are the most common solution, though refractive laser surgery has increased in popularity. One of the procedures is LASIK, in which corneal tissue is removed to reduce the length of the eye. LASIK is different from some other laser procedures because the corneal tissue removed comes from underneath rather than from the surface of the cornea.

Only certain myopia cases are suitable for the surgery. There are some other controversial options like orthokeratology and corneal refractive therapy, which involves wearing specially shaped contact lenses that can temporarily reshape the cornea. Finally, phakic IOLs, a new surgical procedure for extreme myopic cases, are an option that consists of a permanent implantable lens that helps to correct nearsightedness.

Sources:

• AccessScience.com
• The Eye and Visual Nervous System: Anatomy, Physiology and Toxicology – Connie S. McCaa Environmental Health Perspectives (NIEHS)
• Refractive Surgery Center
• Eye Studies; a Series of Lessons on Vision and Visual Tests – Johnston, J. Milton
• The Myopia Myth – Rehm, Donald S
• AllAboutVision.com
• American Optometric Association